SELECT 
  1 
FROM 
  cscart_lock_keys 
WHERE 
  key_id = '5d08146365793123736761637f4af98fcc58900ad41054670c60e4f1e76fb8c4' 
  AND token = '7lO/0FW+Bwfn6kf8oHDyNZg24ZrKn5lcRl5ttJTWQD4=' 
  AND expiry_at > UNIX_TIMESTAMP(NOW())

Query time 0.00025

JSON explain

{
  "query_block": {
    "select_id": 1,
    "message": "no matching row in const table"
  }
}